Wednesday, October 9, 2013

Are Swiss Form Claims a Matter of Substance?

Novartis v Cobalt / zoledronate (NOC) 2013 FC 985
            2,410,201 – ACLASTA

It is now well-established in the Federal Courts that methods of medical treatment are not patentable, but how to define such unpatentable methods is very much an open question. In Cobalt / Zoledronate Hughes J, has reviewed and summarized the Supreme Court and Federal Court jurisprudence on this point, before concluding that all the claims at issue were unpatentable. In my view, to the extent his conclusions of law are supported by  the jurisprudence, they do not justify his conclusion on the facts that the Swiss form claims are to unpatentable subject matter.

Zoledronate is a bisphosphonate. Bisphosphonates generally, and zoledronate in particular, were known compounds which were known to be useful for the treatment of osteoporosis. The inventors of the ‘201 patent had discovered that zoledronate could effectively treat osteoporosis even if administered only once a year. The claims in the ‘201 patent included Swiss form claims (claims 1-9), as well as use claims (10-18) compound claims (19-27), pharmaceutical composition claims (28-36), all for the treatment of osteoporosis when administered one a year [46]. The only issues were obviousness and whether the subject matter was ineligible for patent protection as being a method of medical treatment. Hughes J held on the facts that the invention was not obvious [69]. The evidence showed that a once a year administration was surprising and contrary to conventional wisdom, particularly in light of the fact that bone “remodelling” (the cycle by which bone material is entirely replaced) takes about 100 days. That the effects of zolendronate could extend beyond a cycle was surprising, and the predominant view was that daily or weekly dosing was required [66]. Thus, the invention appears to have been a real breakthrough, and not mere evergreening.

The main question, then, was whether the invention was patentable subject matter. Zoledronate raises three questions. First, it is right to conclude that methods of medical treatment are unpatentable as a matter of Canadian law? Second, if so, what defines an unpatentable methods of medical treatment? Thirdly, what is the effect of Swiss form claims?

The starting point in the SCC jurisprudence on patentability of methods of medical treatment is Tennessee Eastman[1974] SCR 111, in which the patent at issue was for a surgical method for bonding wounds with known compounds. It was decided when s 41(1) of the Act was in force, prohibiting compound claims to pharmaceuticals. The SCC held that

It is clear that a new substance that is useful in the medical or surgical treatment of humans or of animals is an "invention". . . . But what of the method of medical or surgical treatment using the new substance? Can it too be claimed as an invention? . . . I do not think so, and it appears to me that s.41 definitely indicates that it is not so.

The SCC went on to point out that “if a method of treatment consisting in the application of a new drug could be claimed as a process apart from the drug itself, then the inventor, by making such a process claim, would have an easy way out of the restriction in s.41(1).”

The logic with respect to s 41 is compelling: a prohibition on claims to pharmaceutical compounds is only effective if claims to the medical use of those compounds is also prohibited. But that rationale is no longer effective with the repeal of s 41(1), so the authority of Tennessee Eastman turns on the quoted paragraph to the effect that “I do not think” that methods of medical treatment are patentable. Subsequent discussion of Tennessee Eastman in Shell Oil [1982] 2 SCR 536, 554 and Wellcome / AZT 2002 SCC 77 [49] were similarly ambiguous, explaining it both as being “based on” s 41, and on the basis that methods of medical treatment “essentially non-economic and unrelated to trade, industry, or commerce. [The patent] was related rather to the area of professional skills.” Both cases distinguished Tennessee Eastman, so the holding on the facts do not help us decide what was the main basis for the decision.

Nonetheless, the Federal Courts have consistently interpreted Tennessee Eastman as holding that methods of medical treatment are not patentable. I suspect that if the matter were to go to the SCC, it would not feel itself bound by its previous decisions to hold that methods of medical treatment are unpatentable. But at the same time, there are enough hints to that effect that the Federal Courts’ interpretation is a reasonable one. Thus the point can be considered well-established, at least until the issue is taken up by the SCC.

The real debate has been over how to define unpatentable methods of medical treatment. Hughes J summarized the jurisprudence as follows:

[91] What the jurisprudence establishes is that a claim to a vendible product, including a substance intended for the treatment of a medical condition, can be good subject matter for a patent claim. Thus, claims such as the following are proper subject matter:
• the substance X for the treatment of Y
• the substance X in the form of a 5 mg tablet for the treatment of Y

[92] What is improper subject matter is a claim that encompasses the skill of a medical professional, such as:
• the closure of a surgical incision by the use of adhesive X
• the use of substance X in a dosage range between A and B for the treatment of X

Contrast the first item in each pair. On its face, it is a fine distinction between a patentable “compound X for the treatment of a disease,” and “the use of compound X for treatment of a wound” which is not. Surely there is no distinction to be made between medical and surgical methods; the jurisprudence has always treated thrm on the same footing – Tennessee Eastman is the leading authority for the unpatentability of medical methods, not just for surgical methods – and I can think of no reason for distinguishing them.

The only other evident basis for the distinction is that the patentable claim is to a compound, while the unpatentable claim is to a method. That a claim to “the substance X for the treatment of Y” is patentable is established by Wellcome / AZT, and that “the closure of a surgical incision by the use of adhesive X” is unpatentable is established by Tennessee Eastman (if we accept that it did not turn on s 41), so it is helpful to consider the specific claims at issue in those cases. In Wellcome / AZT the key independent valid claim in patent 1,238,277 was as follows:

22. A pharmaceutical formulation for use in the treatment or prophylaxis of AIDS comprising an effective amount of [AZT].

In Tennessee Eastman the key claim (see the Ex Ct decision, 62 CPR 117, 121) was to:

1. The method for surgical bonding of body tissues which comprises applying to at least one of the tissue surfaces to be bonded an adhesive composition comprising [specified known compounds]

There is a distinction here between a claim to a compound for use and a method of using a compound. That Hughes J saw this as the basis for the distinction between the claims is indicated by his emphasis that claims to a “vendible product” are patentable in [91] and elsewhere, including his description of Wellcome / AZT as a case in which a vendible product was claimed [78] (and see [81], [83], [87]); a compound (for a use) is a vendible product, while a use (for a compound) is not. But this may seem to be a distinction of form rather than substance, as it implies that a claim to “a compound for use in surgical bonding of body tissues” would be valid, even though a claim to “a method for surgical bonding” using the same compound is not. A judicially created doctrine, like a statute, should be interpreted purposively. To decide whether this distinction is sound, we need to know the reason why methods of medical treatment are unpatentable.

Tennessee Eastman is entirely unhelpful in this regard. The discussion omitted from the quotation given above, which provided the basis for not thinking that methods of medical treatment are patentable, is as follows:

In order to establish the utility of the substance this has to be defined to a certain extent. In the case of a drug, the desirable effects must be ascertained as well as the undesirable side effects. The proper doses have to be found as well as methods of administration and any counter-indications. May these therapeutic data be claimed in themselves as a separate invention consisting in a method of treatment embodying the use of the new drug?

This is all true, but it provides no basis for concluding the such methods should not be patentable. On the contrary, the fact that, eg desirable effects of a drug must be found, is a reason why claims to the use of a drug should be patentable, in order to provide an incentive for that research. Indeed, it is, presumably, the reason why s 41 was repealed.

Wellcome / AZT is more helpful. The SCC explained as follows:

The policy rationale [for the decision in Tennessee Eastman], as explained by Wilson J. in Shell Oil, supra, at p. 554, was that the unpatentable claim was

essentially non-economic and unrelated to trade, industry, or commerce. It was related rather to the area of professional skills.

The assertion that professional skills, including engineering and law (see Lawson 62 CPR 101) are “essentially non-economic” and “unrelated to trade, industry or commerce,” is curious. The origin of this concept is discussed below. For now it is enough to note that this explanation, such as it is, cannot distinguish the claims at issue in  Wellcome / AZT from those at issue in Tennessee Eastman. Treating a disease and treating a wound both relate equally to the human body, and both relate equally to the area of professional skills.

But the SCC continued:

50 The AZT patent does not seek to "fence in" an area of medical treatment. It seeks the exclusive right to provide AZT as a commercial offering. How and when, if at all, AZT is employed is left to the professional skill and judgment of the medical profession.

This seems to be saying that there is a difference of substance in terms of infringement. A patent confers the right to make, sell or use the invention: s 42. The use of AZT to treat HIV/AIDS is clearly a medical treatment, so the SCC seems to be saying that the AZT patent does not “fence in” an area of medical treatment because the claim to “the compound for the use” is infringed only by the manufacturer and vendor who provides the compound for that use “as a commercial offering,” and not by the user of the compound. In contrast, a claim to the use of the compound would be infringed by the physician who administers it.

So, on this view the difference between “Compound X for use” in medical treatment, and “the use of Compound X” for medical treatment, is a matter of substance, not form, as it determines whether a medical practitioner will infringe. This also implies a coherent policy rationale for the exclusion, namely that medical practitioners should be free to treat their patients to the best of their ability, without fear of a patent infringement action. That rationale is the basis for the US rule, codified in 35 USC § 287(c)(1), which permits patents on methods of medical treatment, but restricts remedies against medical practitioners. That is also the purpose of the prohibition on patenting methods of medical treatment in EPC Art 53(c): see Actavis UK Ltd v Merck & Co Inc / finasteride [2008] EWCA Civ 444 at [51], [58]-[59], [75]. The US prohibition protects medical practitioners by allowing patents, but making them in effect unenforceable against practitioners, while the EPC provision achieves the same end by prohibiting patents which could be enforced against medical practitioners, while permitting patents which are enforceable only against others in the supply chain. On the theory just discussed, the Canadian rule is essentially a common law version of EPC Art 53(c), with the same rationale. This rationale explains why use patents are generally permissible, but medical use claims are not; protecting medical practitioners ability to treat their patient raises ethical issues that do not arise in, for example, the use of a compound as a weed-killer.

To recap, the most obvious way to reconcile Wellcome / AZT and Tennessee Eastman is on the basis of the repeal of s 41. If we reject this basis, then the difference between the “composition for use” claim in Wellcome / AZT and the “method of using a composition” claim in Tennessee Eastman, is that the latter, but not the former, would make the physician an infringer. The way to distinguish a claim to a method of medical treatment is to ask whether a physician who applies the inventive concept of the invention in treating a patient would infringe the patent. If she would, it is an unpatentable method of medical treatment; if she would not, it is a patentable claim to a medical compound.

There is, however, a difficulty with this rationale as an explanation for Hughes J’s decision. As noted at the outset, the claims in the ‘201 patent included Swiss form claims as well as use claims. The parties focused on Claim 7, a Swiss form claim to the use of zolendronate in the manufacture of a medicament for the treatment of osteoporosis. Consequently, counsel for Novartis argued that the patent claims a vendible product, namely a bottle of zolendronate for use in a once-a-year treatment of osteoporosis. Hughes J rejected this, and focused Claim 16, a use claim, to use of zolendronate for the treatment of osteoporosis on a yearly dosage regime [48]. He said that

this Court should disregard the artificial nature of a Swiss claim and look at what is the real subject matter of the claim. Here the invention is, as previously discussed, the recognition that zoledronate can be administered infrequently, such as once yearly injections of 5 mg, and provide effective treatment for osteoporosis. It is in reality, however contrived the wording of the claim may be, a method of medical treatment; hence, under Canadian law, unpatentable [101].

That is, Hughes J was of the view that there is no difference between a claim to a compound for a use, and a claim to the use of a compound. Hughes J said that it was necessary to look at what is "the real subject matter of the claim," but in fact he looked at the inventive concept, rather than the claim, holding that if the inventive concept is a method of medical treatment, the claims are invalid, regardless of their form. 

But as just discussed, the form of the claim is actually a point of substance, as a Swiss form claim will never be infringed by a doctor who uses zolendronate to treat osteoporosis. A Swiss form claim does not "fence in" an area of medical treatment, but only seeks an exclusive right to provide the drug as a commercial offering. This is the very point of Swiss form claims. As Jacob LJ noted of the Swiss form patent at issue in Actavis / finasteride, “It is not aimed at and does not touch the doctor - it is directed at the manufacturer” [75] (see also ibid [58]-[59]). Thus, on the theory discussed above, a Swiss form claim is not a claim to a method of medical treatment, because a physician would not infringe, even if they used the inventive concept disclosed in the patent in treating a patient. 

Conversely, if it is the inventive concept, and not the claim that must be considered, then how is Wellcome / AZT to be explained? The inventive concept there was the discovery that AZT, a known compound, is effective to treat a particular disease. The inventive concept in Zoledronate is that a once yearly dosing of a known compound is effective to treat a particular disease. The only difference is that the inventive concept in Zoledronate relates to a dosage regime. Surely giving a drug to treat a disease is a method of medical treatment, just as much as is giving a drug at a particular schedule; a particular type of dosage regime is just one aspect of medical treatment. Similarly, there is no distinction between Wellcome / AZT and Tennessee Eastman at the level of inventive concept; in one it is the use of compound X to treat a disease, in the other it is the use of compound X to treat a wound. At the level of inventive concept, both are equally methods of medical treatment. Zoledronate can of course be distinguished on the basis that it claims a dosage regime, but there is no reason in principle to single out dosage regimes as such; if dosage regime are unpatentable, it is because they are unpatentable methods of medical treatment.

In summary, if Wellcome / AZT and Tennessee Eastman are to be distinguished as discussed above, then, contrary to Hughes J’s holding, the Swiss form claim 7 and the use claim 16, can be distinguished on the same basis. The distinction is one of substance, not form, as it impacts who will be an infringer. On the other hand, if we are to assess whether a claim is to a method of medical use on the basis of the inventive concept, rather than on the basis of the claims, all the claims of the ‘201 patent are invalid, but the claim held valid by the SCC in Wellcome / AZT would be invalid on the same basis.

There is, however, another strand in the jurisprudence identified by Hughes J, which is illustrated by the second pair of contrasting claims he identified at [91]-[92]:

• the substance X in the form of a 5 mg tablet for the treatment of Y [patenable]
• the use of substance X in a dosage range between A and B for the treatment of X [unpatentable].

These claims also contrast substance claims with use claims, and to that extent are subject to the discussion above. But they also capture a distinction between a precise dosage and a dosage range. This adverts to quite a different rationale. The use of a precise dosage and the use of a dosage in a range are evidently both equally methods of medical treatment, particularly as the substance and the compound might both be the same. The objection is that the latter claim, but not the former,“encompasses” the exercise of professional skill: [92]; and see [83], [85], [87], [89].

This distinction between a specified dose and a dosage range is well supported by the FC case law reviewed by Hughes J (see Axcan / ursodiol (NOC) 2006 FC 527, Harrington J andJanssen / galantamine (NOC)2010 FC 1123 Barnes J holding claim to dosage range unpatentable; Merck / finasteride (NOC) 2010 FC 510 Hughes J holding a claim to a specific dosage amount patentable.) However, this distinction is difficult to reconcile with Wellcome / AZT. Here, again, is the key valid claim at issue in that case (my emphasis):

22. A pharmaceutical formulation for use in the treatment or prophylaxis of AIDS comprising an effective amount of [AZT].

The claim is not to a tablet in the form of a specified dosage. The patent teaches that AZT is effective in treating HIV/AIDS, but the claims leave it up the skill and judgment of the physician to determine what an effective amount would be. It requires even more skill and judgment than a claim to a dosage range, which Hughes J considers to be unpatentable, because the dosage range provides some guidance, while the AZT claim doesn’t specify a range, but requires the physician to exercise medical judgment to determine what is an effective dose. If the former claim “encompasses’ the exercise of skill and judgment, the latter claim does a fortiori.

As noted above, the best way to interpret a common law doctrine is to understand its purpose. What is the purpose behind the prohibition on patenting of patents related to professional skill? There is no clear answer to this question. In the leading cases, the position that professional skills are unpatentable has been the statement of a conclusion, rather than a reason for arriving at that conclusion. The statement in Shell Oil, quoted in Wellcome / AZT to the effect that professional skills are not patentable, was provided by the SCC as an explanation of the Ex Ct decision in Tennessee Eastman (1970), 62 CPR 117 (Ex Ct) and the decision of the Ex Ct in Lawson v. Com’r of Patents (1970), 62 CPR 101 (Ex Ct). In turn, both these cases base this proposition on the great case of NRDC (1961) 102 CLR 252 (HCA), the Australian equivalent of Shell Oil, in which the High Court of Australia held that the use of a known compound for the purpose of eradicating weeds was patentable. In the course of so holding, the HCA at 275 (citations omitted) remarked, in a passage quoted in both Ex Ct decisions, that processes are patentable if the processes relates

to a useful art as distinct from a fine art. . . that its value to the country is in the field of economic endeavour. (The exclusion of methods of surgery and other processes for treating the human body may well lie outside the concept of invention because the whole subject is conceived as essentially non-economic)

The HCA did not hold that methods of medical treatment are essentially non-economic; rather it offered this as a possible explanation for the existing exclusion of methods of medical treatment. The HCA was not particularly enthusiastic about this exclusion. The HCA at 270 favoured the view that “it is enough that a process produces a useful result” and “ something that can be made by man from the matters subjected to his art and skill, or at the least some new mode of employing practically his art and skill” (HCA emphasis, citations omitted). This would evidently cover methods of medical treatment, as being useful and a new mode of employing a skill, but the HCA cautioned that “ The need for qualification must be confessed, even if only in order to put aside, as they apparently must be put aside, processes for treating diseases of the human body” (270, my emphasis, citations omitted). Thus, the characteriztion of methods of medical treatment as essentially non-economic was merely an attempt, which did not entirely convince the HCA, to distinguish prior cases. It is not a rationale which justifies the distinction. Similarly, Shell Oil’s embrace of the “professional skills” exclusion was made in the course of distinguishing Lawson and Tennessee Eastman. Neither was the SCC was enthusiastic about the limitation, immediately remarking that in Tennessee Eastman “The [Supreme] Court, however, affirmed that ‘art’ was a word of very wide connotation” that was to be “extended . . . to new and innovative methods of applying skill or knowledge provided they produced effects or results commercially useful to the public.” On its face, a new and inventive dosage regime falls squarely within a method of applying knowledge which produces effects useful to the public. So, in both the HCA and the SCC, the professional skills exclusion was employed as a means of reconciling prior cases, and no independent rationale for the exclusion is provided.

(I can't leave NRDC without noting that it was a powerful repudiation of the "vendible product" test for patentable subject matter test. To the extent that the discussion above supports such a test, it is only in respect of methods of medical treatment, and not as a general test.)

While there is no guidance from the leading cases as to a justification for the exclusion of the exercise of professional skill, I suggest that is a rationale that may be applicable in some cases. Professional skill often reflects a multitude of subtle practices that have accumulated over years of experience. These skills can be capable of general definition, yet precisely because the general strategy is instantiated by a variety of specific practices, it may be difficult to define how to practice the skill. For example, a lawyer who is skilled in cross-examination may say “I like to establish a rapport with the witness” or “I like to intimidate the witness,” but how exactly this is done is difficult to define. A few tricks might be described, but the skill must ultimately be learned by experience and practice – which is why it is referred to as a skill rather than a rule. It seems evident that such skills should not be patentable, and I suggest that this may underpin the intuition that professional skills are unpatentable. But this rationale only applies to certain types of professional skill, namely those which cannot be precisely defined. Any claim to such a skill would be unpatentable in any event, as being vague or insufficiently disclosed. This objection does not apply to skills that can be sufficiently precisely defined to be susceptible of effective use on the disclosure in a patent.

The jurisprudence on methods of medical treatment is difficult, but in my view, the best principled basis for a prohibition of patents on methods of medical treatment is that it protects the freedom of a physician to treat their patient as they think best, without fear of a patent infringement. This has an evident policy appeal; it allows Wellcome / AZT and Tennessee Eastmanto be reconciled without reference to the repeal of s 41; and it has some direct in Wellcome / AZT. Whether it is appropriate for the courts to create a policy based exception of this type, particularly in dicta, is another question, but, on the assumption that methods of medical treatment are unpatentable, this is the best justification. But if that is the true purpose of the rule, then the Swiss form claim in the ‘201 patent are valid.

5 comments:

  1. I think you have made a small error. You say:

    "Contrast the first item in each pair. On its face, it is a fine distinction between a patentable “compound X for the treatment of a disease,” and “the use of compound X for treatment of a wound” which is not."

    However," the use of compound X for treatment of a wound" is patentable. I believe you meant to compare,“compound X for the treatment of a disease,” and "the closure of a surgical incision by the use of adhesive X". Even this last phrase is not accurate. Hughes J was really talking about "a method of closing incisions following surgery by the use of an adhesive substance". This is a method of medical treatment.

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  2. Anon, thank you for your thoughtful comment. I am away from the office this week, but I will think through your point more carefully when I return next week.

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  3. Anon,

    You are right that I have paraphrased the specific examples given by Hughes J. But to my mind, my paraphrase has not changed the substance. The phrase Hughes J used in [92] was “ the closure of a surgical incision by the use of adhesive X,” which was itself a paraphrase of the Tennessee Eastman claim to “The method for surgical bonding of body tissues which comprises applying [an adhesive].” Hughes J’s paraphrase omits the word “method” and refers only to “use.” So, I have further paraphrased Hughes J by substituting “treatment of a wound” for “closure of a surgical incision,” on the view that a surgical incision is a wound, albeit one that is inflicted with beneficial intent, and closing a wound is a way of treating the wound. It seems to me that if there is any distinction to be made between these formulations it is a very fine one.

    Put another way, you say "the use of compound X for treatment of a wound" is patentable. This implies that if the patentee in Tennessee Eastman had also claimed “the use of adhesive X for surgical bonding of body tissues” that would have been held patentable, even though “the method for surgical bonding of body tissues” was not. I doubt that is so. The examiner has refused to grant the patent on the basis that “"The applicant is claiming the use of a substitute analogous adhesive in a known surgical process . . . . The use of such an adhesive in such conditions is strictly in the medical arts. . . .” (62 CPR 117, 121). The examiner clearly drew no distinction between a method claim and a use claim, and I very much doubt that the SCC would have drawn any such distinction either.

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  4. Anon,

    I should add something. I see your point that " the use of compound X for treatment of a wound" must be patentable, because medical use claims (eg AZT for the treatment of HIV/AIDS) are patentable, and I agree that such a claim is patentable. My point is that it is very difficult to distinguish these patentable claims from unpatentable methods of medical treatment.

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    Replies
    1. Point taken. Thanks for the thoughtful remarks.

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